1. Field of the Invention
The present invention relates to slide fasteners, and more particularly to a slide fastener stringer including a woven stringer tape and an elongate strip of thermoplastic molded coupling elements woven into the stringer tape along a longitudinal edge thereof.
2. Prior Art
Various slide fastener stringers are known in which an elongate strip of thermoplastic molded coupling elements interconnected by molded connecting portions extending integrally with and between adjacent coupling elements, is attached to a woven stringer tape along a longitudinal edge thereof. One example of such known stringers is disclosed in Japanese Patent Laid-open Publication (Kokai) No. 57-31802 published on Feb. 20, 1982. (Corresponds to U.S. Pat No. 4,429,438, issued Feb. 7, 1984.) According to this disclosed slide fastener stringer, an elongate molded coupling element strip includes a plurality of laterally spaced coupling elements each having a pair of upper and lower legs, and a pair of series of first and second connecting portions extending integrally with and between alternate pairs of the upper legs and alternate pairs of the lower legs, respectively, in staggered relation to one another. The coupling element strip is secured by the plurality of loops of a single weft thread to the longitudinal edge of a stringer tape woven of a plurality of warp threads and the weft thread. The loops encircle alternate ones of the first and second connecting portions and a pair of anchor threads (FIG. 10) respectively disposed in a pair of grooves extending transversely of the upper and lower legs, respectively, in substantial alignment with the connecting portions. Since each weft loop is open widely in a direction perpendicular to the general plane of the stringer tape, it urges the anchor threads toward each other between adjacent coupling elements to hold the individual coupling elements firmly in position. However, because each connecting portion extends longitudinally of a respective one of the legs to the middle of the same, and because the anchor threads are urged by the weft loops to lie on and along the molded connecting portions, the stringer has a limited degree of flexibility which hinders smooth movement of a slider on the slide fastener.